INTERACTIONS IN THE SPHALERITE-CA-SO4-CO3 SYSTEMS

The interaction of sphalerite with calcium, sulphate and/or carbonate was studied using zeta potential measurements, scanning electron micro scopy, and X-ray photoelectron spectroscopy. The interaction in the Ca and Ca-SO4 systems appeared to be the same, namely adsorption of ioni c Ca species in the double layer. Neither Ca nor CaSO4 was detected by surface analysis. In the Ca-CO3 system, some CaCO3 precipitates were found on the surface. Addition of increasing CO3 to the Ca-SO4 system progressively converted CaSO4 to CaCO3 precipitates and the system eve ntually became identical to Ca-CO3 alone. The role of CO3 addition in flotation appears to be to remove ionic calcium species, whether SO4 i s present or not. (C) 1998 Elsevier Science B.V.